We must suppose it to be so, but it does not follow that we can know anything about it if it is divided into pieces smaller than a certain size; and, if we can know nothing about it when so divided, then, _qua_ us, it has no existence and therefore matter, _qua_ us, is not infinitely subdivisible. Differences We often say that things differ in degree but not in kind, as though there were a fixed line at which degree ends and kind begins. There is no such line. All differences resolve themselves into differences of degree. Everything can in the end be united with everything by easy stages if a way long enough and round-about enough be taken. Hence to the metaphysician everything will become one, being united with everything else by degrees so subtle that there is no escape from seeing the universe as a single whole. This in theory; but in practice it would get us into such a mess that we had better go on talking about differences of kind as well as of degree. Union and Separation In the closest union there is still some separate existence of component parts; in the most complete separation there is still a reminiscence of union. When they are most separate, the atoms seem to bear in mind that they may one day have to come together again; when most united, they still remember that they may come to fall out some day and do not give each other their full, unreserved confidence. The difficulty is how to get unity and separateness at one and the same time. The two main ideas underlying all action are desire for closer unity and desire for more separateness. Nature is the puzzled sense of a vast number of things which feel they are in an illogical position and should be more either of one thing or the other than they are. So they will first be this and then that, and act and re-act and keep the balance as near equal as they can, yet they know all the time that it isn’t right and, as they incline one way or the other, they will love or hate. When we love, we draw what we love closer to us; when we hate a thing, we fling it away from us. All disruption and dissolution is a mode of hating; and all that we call affinity is a mode of loving. The puzzle which puzzles every atom is the puzzle which puzzles ourselves—a conflict of duties—our duty towards ourselves, and our duty as members of a body politic. It is swayed by its sense of being a separate thing—of having a life to itself which nothing can share; it is also swayed by the feeling that, in spite of this, it is only part of an individuality which is greater than itself and which absorbs it. Its action will vary with the predominance of either of these two states of opinion. Unity and Multitude